Seeing a reproducible LangSmith Playground failure:
Both endpoints return 401:
- POST /playground/stream
- POST /playground/invoke
Response:
{“detail”:“Invalid token”}
Reproduces across:
- multiple accounts (work + personal)
- multiple workspaces (including brand new ones)
- incognito sessions
- multiple providers (OpenAI + Gemini)
- saved + fresh prompts
Note:
This is NOT limited to streaming as /invoke fails as well.
The failing Authorization header is the LangSmith session JWT (not provider key) and the request fails before any provider call is made.
Other LangSmith UI functionality works normally.
Conclusion:
This appears to be a backend auth regression affecting Playground execution endpoints.
If helpful, I can provide:
- exact timestamps (UTC)
- tenant IDs
- sanitized request/response logs
Happy to help debug further.